1. Field of the Disclosed and Claimed Inventive Concepts
The presently disclosed process(es), procedure(s), method(s), product(s), result(s), and/or concept(s) (collectively referred to hereinafter as the “present disclosure”) relates generally to a lactam-functionalized polymer comprising a polymer backbone and at least one lactam moiety attached to the polymer backbone. In particular, the polymer backbone can be polyacetal polyether, polyhemiaminal polyether, or polyaminal polyether. Additionally, the present disclosure relates generally to compositions comprising the lactam-functionalized polymers and applications thereof in various industrial areas such as coatings.
2. Background and Applicable Aspects of the Presently Disclosed and Claimed Inventive Concept(s)
Water-soluble polymers (also commonly referred to as “thickeners” or “rheology modifiers”) are widely used in many industrial water-borne systems as additives to modify their flow behavior. Thickeners increase and maintain viscosity at required levels under specified processing conditions and end use situations. Thickeners are useful, for example, in decorative and protective coatings, paper coatings, cosmetics and personal care products, detergents, pharmaceuticals, adhesives and sealants, agricultural formulations, and petroleum drilling fluids.
One such highly filled aqueous system where the thickener is used in a decorative and protective coating is latex paint, which is composed of a dispersion of polymeric latex, pigments, clays, and other additives in water.
Thickeners can be materials that are either naturally existing or synthetically manufactured. Natural thickeners, for example, can include casein, alginates, gum tragacanth, guar, xanthan gum, locust and bean gum. Typical examples of naturally derived thickeners can include cellulose ethers derived from celluloses, such as hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), and carboxymethyl cellulose (CMC). These natural and naturally derived products (hereinafter called “natural products”) vary in their thickening efficiency. One of the drawbacks of the naturally based thickeners is that they are subject to microbial attack and hence, addition of antimicrobial agents to the formulation is required. Synthetic thickeners include various acrylic polymers, alkylene oxide polymers, amide polymers, and maleic anhydride polymers. These synthetic thickeners can be either homopolymers or copolymers. The hydrolytic stability of some polymers depends on the pH of the solution and others are sensitive to various components normally found in aqueous coatings.
Typically, a small amount (about 0.1-5.0 wt %) of water-soluble polymer is added to latex paint to achieve the following performance characteristics during manufacturing, storage, and applications: a) ease of formulation, b) prevention of settling of the suspended particles (latex, pigment, etc.) during storage, c) good film build during applications to achieve efficient hiding without excessive brush or roller drag, d) good roller spatter resistance, e) no excessive sagging after application on a vertical surface, and f) good flow and leveling for the formation of a smooth and continuous film with good appearance.
The above mentioned natural and synthetic thickeners provide different degrees of thickening efficiency and application properties. However, they invariably fail to provide all of the key performance properties in gloss paints. These key properties include good film build, flow and leveling, and gloss which are generally offered by solvent-based alkyd paints. Another drawback of these thickeners is that they may have poor compatibility with the various paint ingredients.
To eliminate the performance deficiencies of the conventional thickeners, a new class of thickeners, commonly referred to as “associative thickeners”, has been developed and commercialized (See E. J. Schaller and P. R. Sperry, in “Handbook of Coatings Additives”, Ed. L. J. Calbo, Vol. 2, p: 105, 1992; Marcel Dekker, Inc., New York). These thickeners include hydrophobically-modified water-soluble polymers. They undergo intermolecular association in aqueous solution and thereby exhibit enhanced solution viscosity. They can also adsorb onto the dispersed-phase particles of an aqueous dispersion and thereby form a three-dimensional network. Since they provide improved paint properties not offered by conventional thickeners, they have gained commercial importance.
Commercial nonionic synthetic thickeners exhibit often poor and variable compatibility in paints, as exemplified by syneresis, poor color acceptance, variable paint viscosity over time, and inadequate hiding power.
It has been found that novel polymers and compositions according to the present disclosure can provide, among many other performance attributes, the important benefits of improved rheological properties. The polymers and compositions thereof may advantageously be used in various industrial applications including coatings. Non-limiting examples of coating applications include improved hide of the coating compositions on substrates.